Step 1: Parts and Stuff

1 USB cable (can be ANY of the three types shown below, as long as it has the same wire layout

Some (tiny amount) solder

Switch (optional)

Nescessary tools (wire stripper/cutter, soldering iron, tape)

Step 2: The Building

The buildig part is really simple.

First, cut the cable at the non-male end( its usually square or smll). Then strip the USB cable and solder thee RED and BLACK wires to their respective contacts on the motor (experiment to see which way makes the prop will push the air FORWARD)

If you're adding a switch, you might need to solder some extra wire depending on where you want it to go, but I didnt 'cause its more practical to use the plug as a switch).

you are complaining about your 3 year old computer??? Mine is 5 years old and still works just fine! Many people in other countries would be glad to have you computer. You should be thankful for what you have! You dont need a new computer every year!

I am not an electrical engineer,yet this will work. What I am not sure of is the effect on the internal circuitry without voltages being a constant.So in essence, it works, but prolonged usage may have consequences,( unless there is an engineer that can reiterate on this). My modem was overheating, so I placed a USB fan next to it and it works great! Your homemade version is the same thing, except I know that my fan was engineered for this purpose. See attached photo:

pretty good i must say..but what if you accidentally stop the fan with your hands?the motherboard will get burned and you cant use ur pc anymore...happened to my laptop when i plugged in my flash drive with twisted leads.my laptop usb drive works nomore.

No, the motherboard will not fry, the usb section has a current limiter, and all of that safety stuff, so that if you were dumb enough to put your hand in the way of the fan in the first place, then it wouldn't cost you a comp.

"Since I used a 3-Volt motor, and the Computer's Output is 9 Volts" I believe the power rail in USB is at 5 volts, not 9, so your 3V fan can probably deal with it for a while at least. If you want it to run slower you might want to put a resistor (a variable resistor would be better) in series with it to limit the voltage.

Erm.. yes and no. People seem to be most familiar with current limiting resistors used with LEDs, but in a circuit with a resistive load like a motor or a lightbulb, they are actually controlling voltage. The current then decreases because of the lower voltage. Your nearest physics or electronics textbook can probably explain it better than I can.